This invention relates to an arrangement for the pneumatic removal of bulk particulate material, for instance, grain and the like, from the floor of a storage place by directed streams of pressure air. The arrangement of the invention also permits an aeration of the stored material by cold or warmed air, as desired.
Known arrangements for the removal of bulk particulate material from storage places employ either mechanical or pneumatic transport systems.
Known mechanical systems for the emptying of the floor of storage places employ transport systems such as band, chain, worm, and similar conveyors. Such conveyors are usually mounted on or above the level of the floor of the storage place, or in some instances they are portable. Such mechanical material transporting means usually are employed in combination with different collecting means such as mechanical shovels, submerged screw conveyors, and the like. In some cases the correcting of the material is carried out manually by shovels. This method of removing bulk particulate material from floor storage places is most widely used; however, it requires a number of mechanical material transporting means with their respective driving units, and consequently involves substantial expenses for the purchase of the equipment, for maintenance, for the distribution of electricity to the driving means, and the like. With such arrangements there are frequent failures of the mechanical units, and thus substantial lost time, particularly in view of the large number of mobile components in the arrangement. Further, one or more attendants are required to operate the mechanical collection means or to collect the material manually, such attendants being required to perform their work in a dusty, unhealthful atmosphere. If the bulk particulate material, for instance, grain, is to be aerated by cold or warm air, an additional, special aeration device must be provided.
When the bulk particulate material is removed pneumatically, the pneumatic removal system may be either portable or fixed. Portable arrangements for this purpose use only the suction effect of air which is generated by blowers or ventilators, the removed material being conveyed from the storage place by conduits. This method of emptying storage places requires the presence of an attendant inside the storage place, such as a silo or other storage building, the attendant manually controlling the suction nozzle connected to the material-conveying conduit. In the case of portable arrangements, the attendant controls the travel of the discharge mechanism along the floor of the storage place. This method of material removal does not permit the aeration of bulk particulate material.
Fixedly installed pneumatic devices for discharging bulk particulate material employ the pressure effect of air. In such arrangements, there is usually provided a main channel located along the longitudinal axis of the storage place, where distribution closures for air, or a chain or band conveyor, and further closures for the bulk material are provided. Emptying channels, generally disposed at the level of the floor of the storage place, are connected to the main channel, such emptying channels serving to direct the pressure air against the stored material so as to cause the material to travel toward the main channel.
The drawback of this method of discharging bulk particulate material is the limitation of a planar emptying of the bulk material from the storage space to a distance of 10 meters from the main channel. Furthermore, construction of the main channel with distributing closing means controllable by one or more attendants is intricate and expensive. The further drawback of such arrangement is that the main channel occupies a substantial part of the space within the storage place, thereby reducing its storage capacity. Also, the emptying process has to be interrupted if any adjustments of the closing means in the main channel are required. The closing means have to be controlled by an attendant who must enter the main channel, the space within which is rather limited. Any repairs of the mechanical material transporting means, for instance the chain or band conveyor, also have to be made inside this channel. This method of bulk particulate material discharge involves fairly high investment costs, and makes it practically impossible advantageously to use the floor storage place for other purposes, such as, for example, material in sacks or on pallets.